The present invention relates to a brushless motor fan unit and, more particularly, to a centrifugal type brushless motor fan unit in which a brushless motor and a centrifugal fan are constructed as a unit.
A typical conventional centrifugal motor fan unit has a centrifugal fan attached to the output shaft of a motor, the motor having a motor housing attached to the rear wall of a scroll chamber so that the output shaft may be directed toward the suction port formed in the front wall of the scroll chamber.
In the conventional centrifugal motor fan unit of the type stated above, since the motor having a large weight is supported solely by the rear wall of the scroll chamber, the rear wall is required to have a strength large enough to bear the large weight of the motor. In addition, the output shaft of the motor tends to oscillate undesirably. Furthermore, the presence of the motor housing impractically increases the size of the motor fan unit as a whole, to make it difficult to obtain a compact construction of the motor fan unit. It is also to be pointed out that, since the rotor usually constitutes the armature of the motor, it is not possible to effect the speed control in a simple manner.